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| Titel |
Carbon sources supporting benthic mineralization in mangrove and adjacent seagrass sediments (Gazi Bay, Kenya) |
| VerfasserIn |
S. Bouillon, T. Moens, F. Dehairs |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 1, no. 1 ; Nr. 1, no. 1 (2004-10-28), S.71-78 |
| Datensatznummer |
250000072
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| Publikation (Nr.) |
 copernicus.org/bg-1-71-2004.pdf |
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| Zusammenfassung |
The origin of carbon substrates used by in situ sedimentary bacterial
communities was investigated in an intertidal mangrove ecosystem and in
adjacent seagrass beds in Gazi bay (Kenya) by δ13C analysis of
bacteria-specific PLFA (phospholipid fatty acids) and bulk organic carbon.
Export of mangrove-derived organic matter to the adjacent seagrass-covered
bay was evident from sedimentary total organic carbon (TOC) and
δ13CTOC data. PLFA δ13C data indicate that the substrate
used by bacterial communities varied strongly and that exported mangrove
carbon was a significant source for bacteria in the adjacent seagrass beds.
Within the intertidal mangrove forest, bacterial PLFA at the surface layer
(0-1cm) typically showed more enriched δ13C values than deeper
(up to 10cm) sediment layers, suggesting a contribution from
microphytobenthos and/or inwelled seagrass material.
Under the simplifying assumption that seagrasses and mangroves are the
dominant potential end-members, the estimated contribution of
mangrove-derived carbon to benthic mineralization in the seagrass beds
(16-74%) corresponds fairly well to the estimated contribution of
mangrove C to the sedimentary organic matter pool (21-71%) across
different seagrass sites. Based on the results of this study and a
compilation of literature data, we suggest that trapping of allochtonous C
is a common feature in seagrass beds and often represents a significant
source of C for sediment bacteria - both in cases where seagrass C dominates
the sediment TOC pool and in cases where external inputs are significant.
Hence, it is likely that data on community respiration rates systematically
overestimate the role of in situ mineralization as a fate of seagrass production. |
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